We developed a fully-differential 3-axis accelerometer with a Zigzag-Shaped Z-electrode (ZSZ) for motion controls of automobiles and robots. The ZSZ structure is composed of only two silicon layers of an SOI (Silicon-on- Insulator) wafer. The ZSZ structure consists of two kinds of capacitors in a Z-axis direction. The gaps of the capacitors were designed to be same and the sensor detected a capacitance change precisely. However, small gap differences at the capacitors in the Z-axis direction were appeared and it caused unequal sensitivities. This was because the fabricated sensor chip was warped. To overcome this drawback, we have proposed a novel method for chip-level warp control. The warp control is performed by forming a SiO2 frame on a backside of the chip. The frame works as a stress compensator of thermal expansion. The chip-level warp control demonstrated that gaps of the ZSZ were controlled to be equal and the sensor characteristics were also improved. The chip-level warp control is useful for sensors.
|出版ステータス||Published - 2012 1 1|
|イベント||26th European Conference on Solid-State Transducers, EUROSENSOR 2012 - Krakow, Poland|
継続期間: 2012 9 9 → 2012 9 12
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